Coupled oscillators control morning and evening locomotor behaviour of Drosophila

Article Abstract:

The timing of morning and evening activity in Drosophila derives from two distinct groups of circadian neurons: Morning activity from the ventral lateral neurons that express the neuropeptide PDF, and evening activity from another group of cells, including the dorsal lateral neurons. Although the two oscillators can function autonomously, cell-specific rescue experiments with circadian clock mutants indicate that they are functionally coupled.

A light-entrainment mechanism for the Drosophila circadian clock

Article Abstract:

Drosophila timeless protein (Tim) and period protein (Per) are heterodimeric partners in fly head extracts. This Per-Tim heterodimeric complex, which is under clock control, explains the reciprocal autoregulation of the proteins on transcription. A number of the circadian features of the Tim cycle resemble those of the Per cycle. However, their cycling curves show that Tim rapidly decreases during late night/early morning, releasing Per from the complex. Tim and/or the Tim-Per heterodimeric complex are more direct light-sensitive targets of the Drosophila clock.